You can absolutely take alcohol in your checked suitcase on both domestic and international flights, provided you follow strict safety and customs regulations. According to FAA and TSA guidelines, alcoholic beverages with an alcohol-by-volume (ABV) of between 24% and 70% (most spirits) are limited to 5 liters (1.3 gallons) per passenger and must be in their original, unopened retail packaging. For beverages with less than 24% ABV (like most wine and beer), there is no federal limit on the quantity you can pack in checked bags, though you must stay within your airline's weight allowance. Alcohol over 70% ABV (140 proof), such as certain rums or grain alcohols, is strictly prohibited as it is considered a fire hazard. For international travel, you must also be mindful of the "Duty-Free" limits of your destination country to avoid heavy taxes or confiscation. Always pack your bottles securely in the center of your suitcase, wrapped in soft clothing or specialized "bottle protectors," to prevent breakage and leaks that could ruin your belongings and potentially lead to the airline refusing to transport your bag.